McCullough knows it is not an easy decision to leave home but it is one he feels will benefit young boxers.
“You have to make sacrifices in boxing. I was a homebird growing up. When I went away for a week with the Irish team I was crying to get home,” added McCullough.
“I was contracted to come to Las Vegas for three years and then go back home, but things change, your life changes.
“I love Belfast, I always will, but I love Las Vegas and I’ve lived here longer than I have Belfast now.
“The Irish fighters want to come here now too, and I’m happy they are coming because they are going to learn a lot more.”
A confident Thompson – who enjoyed a decorated amateur career – believes a world title lies in his future.
“I’ll be world champion someday, that’s been my dream since I was a kid,” said the multiple Irish champion.
“I truly believe I’ll be the best to come out of Northern Ireland ever. I’m just going to prove that.”